Mouse optical signal process method and device

ABSTRACT

The present invention discloses a method and a device for processing optical signals in a computer mouse, which is related to electric digital data processing. The method is that the relative displacement vector between the mouse device and the illuminated object surface producing laser speckles is reflected by means of collecting movement information of laser speckle signals. The device for carrying out the method consists of a mouse body; inside said mouse body, an amplifying and shaping module, a direction identifying and counting module and a computer interface circuit for processing photoelectric signals are disposed and connected in sequence, characterized in that, said device further includes at least one laser device and a photo sensor for receiving laser speckle signals from the object surface illuminated by laser beams. Said photo sensor transfers the received photoelectric signals to the amplifying and shaping module. This invention has a simple structure, high technical feasibility and high precision.

TECHNICAL FIELD

The present invention relates to electric digital data processing, andmore particularly, to a method and a device for processing opticalsignals in a computer mouse.

BACKGROUND ART

Since computer mouse came into being at the end of 1968, the followingfour generations, which are divided from a technical view point, havebeen developed,

(1) Mechanical Mouse:

The operation principle of the mechanical mouse lies in the use of therotary ball at the bottom of the mouse, i.e. when the rotary ballphysically contacts the surface of the table and rotates to differentdirections, it drives the pressure rotary shafts in different directionsto rotate. These rotary shafts are connected to a circular coder onwhich contacts are arranged in a circle. The rotation of the rotary ballis transferred through pressure shafts to enable the contacts to be incontact with contact strips so as to produce on-off signals which arefurther transformed into 0-1 signals. These data are further transformedinto two-dimensional X-Y axes displacement signals by means of a specialchip to guide the cursor to move accordingly. Because this type of mouseis of a purely mechanical structure, it has the inherited disadvantagesof low precision and vulnerability, and it is now hardly found on themarket.

(2) Optical-Mechanical Mouse:

The mechanical mouse is substituted by the optical-mechanical mouse.This type of mouse is of a similar structure of the mechanical mouse.The only difference between them is that a different coder is used todetect the movements of the mouse. The coder used in theoptical-mechanical mouse consists of a disc with a plurality of narrowslits, and photo tubes and light-emitting diodes disposed on both sidesthereof. The movement of the disc caused by the rotation of the rotaryball sends on-off signals produced by the cutting off of the light pathto the photo tubes, and the microprocessor inside the mouse will thencalculate the distance and direction of the movement of the mouse basedon these signals and the skewing thereof. Since the kernel positioningmechanism of this type of mouse consists of photo components, it ischaracterized by a longer service life (as compared with thepurely-mechanical mouse) and higher positioning precision. However, asthe basic positioning mechanism of this type of mouse is still themechanical rotary ball, just like the conventional mechanical mouse, itwill cause the cursor to move slowly or jump resulting in wrongpositioning. This is mainly due to the dust attached on the insiderotary shafts. It is necessary to clean it thoroughly before it can beused properly again.

(3) Photo Mouse of the First Generation:

Photo mouse is particularly superior in positioning precision, servicelife and operation hand-feeling because the positioning system ofmechanical structure is not used therein any more.

The photo mouse of the first generation is used with a special mouse padhaving a reflecting surface and very regular grid lines formed by blacklines and blue lines. Two light-emitting diodes are arranged at thebottom of the mouse, with one emitting red light absorbable by bluelines and the other emitting infrared light absorbable by black lines.At the bottom of the mouse, there is also arranged another group ofphoto tubes used to receive the reflected lights. The photo mousedetermines the direction and distance of the mouse on the basis of thesignals reflected after the two groups of lights illuminate the X, Yaxes on the mouse pad. As this type of photo mouse has to be operated ona special mouse pad which needs to be always clean, it is not convenientto use the mouse. Therefore, it has not been popularized widely.

(4) Photo Mouse of the Second Generation:

The photo mouse of the second generation is developed by AgilentTechnologies Co., Ltd. USA. In said mouse, light-emitting diodes areused to illuminate the surface of an object; snapshots are made atpredetermined intervals; and then properties of two pictures areanalyzed and processed to detect the moving direction and value of thecoordinates.

In order to determine the displacement of the mouse, it is necessary toscan the pictures, therefore scanning frequency becomes an importantparameter for assessing the photo mouse. Generally, as a minimumrequirement, a scanning frequency of 1,500 times per second is required.The scanning frequency of some of the products made by MicrosoftCorporation has reached 6,000 times per second. Another parameter thatshould not be neglected is the resolution power of the mouse. Thisparameter is indicated by count per inch (cpi). Generally, theresolution power of the mouse is 400 cpi, i.e. coordinates values aretransmitted for 400 times for every movement of 1 inch (while atpresent, the resolution power of photo mouse of better quality may reach800 cpi).

As mentioned above, the purely-mechanical mouse has already beeneliminated; the optical-mechanical mouse has disadvantages which aredifficult to overcome, such as low positioning precision, unsmoothoperation hand-feeling and function deterioration after long use; thephoto mouse of the first generation has not been popularized widelybecause of the high requirements for use; nevertheless the photo mouseof the second generation has overcome the disadvantage of inconveniencein use of the photo mouse of the first generation, and is characterizedby its high precision and long service life, therefore has occupied aplace in the high-end products market. However, due to the complicatedprinciple and structure, its cost remains high, and due to thelimitation of the technological and cost factors, its reacting speed isnot sufficient.

Contents of the Invention

The object of the present invention is to provide a method and a devicefor processing optical signals in a computer mouse, so as to solve theproblems of inconvenience in use, complexity of technology and high costof the prior art.

The method for processing optical signals in a computer mouse accordingto the present invention is: a method for processing optical signals ina computer mouse, characterized in that, the relative displacementvector between the mouse device and the illuminated object surfaceproducing laser speckles is reflected by means of collecting movementinformation of laser speckle signals.

The relative displacement vector between the mouse device and theilluminated object surface producing laser speckle interferences isreflected by means of collecting movement information of laser speckleinterference signals.

Said laser speckle signals or laser speckle interference signals arereceived by a photo sensor, and said laser speckle signals or laserspeckle interference signals are processed, so as to calculate thequantity of laser speckle pulses or laser speckle interferences pulsesreceived by the photo sensor, and to determine the relative displacementbetween the mouse device and the illuminated object surface producinglaser speckles on the basis of the average size of the laser speckles orthe laser speckle interferences.

Said photo sensor has groups of photoelectric sensing units, whereineach group consists of two or more photoelectric sensing units alignedin a line. After laser speckle signals or laser speckle interferencesignals from the object surface illuminated by laser beams are received,relevant photoelectric signals are amplified and shaped by the group ofphotoelectric sensing units to calculate the size of the component ofrelative displacement vector between the photo sensor and theilluminated object surface in the direction of the alignment ofphotoelectric sensing units. In the meantime, the direction of saidcomponent of the relative displacement vector is determined by theskewing of the electric signals produced by these two or morephotoelectric sensing units.

Said photo sensor has at least two such groups of photoelectric sensingunits, wherein each group consists of two or more photoelectric sensingunits aligned in a line, and at least one of the groups has an aligningdirection different from the others. Two of the groups may intersectwith each other and use common units. After laser speckle signals orlaser speckle interference signals from the object surface illuminatedby laser beams are received, relevant photoelectric signals areamplified and shaped by these groups of photoelectric sensing units, soas to calculate the size and direction of the component of relativedisplacement vector between the photo sensor and the illuminated objectsurface of the respective group. And the relative displacement vectorbetween the photo sensor and the illuminated object surface in thetwo-dimensional plane is calculated on the basis of the size anddirection of the component of said relative displacement vector and theintersection angle between the vectors, said size and direction of thecomponent of relative displacement vector and said intersection angleare calculated by two or more groups of photoelectric sensing units indifferent directions respectively.

The device for processing optical signals in computer mouse for carryingout said method for processing optical signals comprises a mouse body;inside the mouse body, an amplifying and shaping module, a directionidentifying and counting module, and a computer interface circuit forprocessing photoelectric signals are disposed and connected in sequence,characterized in that, said device further includes at least one laserdevice and a photo sensor for receiving laser speckle signals from theobject surface illuminated by laser beams; said photo sensor transfersthe received photoelectric signals to the amplifying and shaping module.

It further includes at least two laser devices and a photo sensor forreceiving laser speckle interference signals from the object surfaceilluminated by laser beams; the laser beams emitted from said two ormore laser devices illuminate on one or more areas of the surfaceproducing laser speckle interferences, wherein each area is illuminatedby at least two beams.

It further includes at least one laser device, a beam splitter and aphoto sensor for receiving laser speckle interference signals from theobject surface illuminated by laser beams; the laser beam emitted fromsaid laser device is split into two or more beams by the beam splitterto illuminate on one or more areas of the surface producing laserspeckle interferences, wherein each area is illuminated by at least twobeams.

The principle and beneficial effect of the present invention are: when abeam of laser illuminates a rough surface of an object, the illuminatedarea does not become bright continuously. On the contrary, there aremany disorderly alternating bright spots and dark spots. This phenomenonis called speckles. As shown in FIG. 1, the speckles exist not only onthe rough surface of an object, but also in the entire space in thevicinity of the rough surface of an object illuminated by laser.

The laser speckle is actually a kind of interference phenomenon causedby the construction and destruction between the scattered light waves oneach area unit of the rough surface of an object, which can be explainedand the general features of which can be derived with the theory oflaser interference.

Theoretical study shows that, if the incidence angle of laser is fixed,the contrast ratio of the speckles is related to the roughness of thesurface of the illuminated object. Many objects used in daily life caneasily meet the requirements of roughness for forming speckles.Experiments have proved that the phenomenon of speckles can be obviouslyobserved when laser beam illuminates on most ordinary objects, such astable surface, paper, textile, common metal, plastics, pottery andceramics surfaces, and glass. The laser speckles may be considereddependent on the illuminated surface of the object, therefore they movealong with the movement of the object. The relative displacement betweenthe object and the observer (device) can be measured on the basis ofthis feature of the speckles.

According to the present invention, the relative displacement vectorbetween the laser signal source in the mouse device and the illuminatedobject surface producing laser speckles is reflected by means ofcollecting movement information of laser speckle signals. This purelyphoto technology overcomes all the disadvantages of the mechanicaldevice. It has a simple structure, high technical feasibility, highprecision, and may greatly increase the precision and speed ofmeasurement with economic methods.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of laser speckles;

FIG. 2 is a schematic view showing the principle of the presentinvention;

FIG. 3 is a schematic view showing the principle of the presentinvention;

FIG. 4 is a schematic view showing the principle of the presentinvention;

FIG. 5 is a schematic view of the embodiment 1 of the present invention;

FIG. 6 is a schematic view showing the principle of the circuits of thepresent invention;

FIG. 7 is a schematic view of the embodiment 2 of the present invention;

FIG. 8 is a schematic view of the embodiment 3 of the present invention;

FIG. 9 is a schematic view of the embodiment 4 of the present invention.

EMBODIMENTS

Hereinafter, the present invention will be described in details withreference to the accompanying drawings and embodiments.

The method adopted in the present invention is: the relativedisplacement vector between the laser signal source in the mouse deviceand the illuminated object surface producing laser speckles is reflectedby means of collecting movement information of laser speckle signals,and the laser speckle interference signals are received by photosensors, and then processed, so as to calculate the quantity of specklepulses received by the photo sensor, and to determine the relativedisplacement vector between the laser signal source and the illuminatedobject surface producing laser speckles according to the average size ofthe speckles.

The size of the laser speckle, i.e., the statistical average value ofdistances between the adjacent brightest point and darkest point, isrelated to the wave length of laser and to the aperture angle of theradiation producing the speckles with respect to the plane determiningthe speckle field. As shown in FIG. 2, the size a of the speckle formedon the screen AB at a distance of L, which is also called “objectivespeckle”, by laser scatter from the circular area of a diameter D, maybe expressed approximately by the following formula 1:σ≈1.2^(λ)L/D

As shown in FIG. 3, if the radiation field of the scatter is focusedonto a screen by a lens, a “subjective speckle” will be formed. Undersuch circumstances, the relationship between the size a of theindividual speckle and the effective numerical aperture N.A. of the lensmay be expressed by the following formula 2:σ≈0.6^(λ)/N.A.

Although the size of the speckles follows the statistical rules of theabove formula 1 or 2, the size of each specific speckle is random,therefore, accurate measurement data cannot be obtained from simplecounting of the pulses outputted and shaped by the photo sensingcomponents. However, since the size of the speckles follows thestatistical rules, the sum (or average value) of the size of a pluralityof speckles (obtainable by adding a plurality of pulses together oraveraging them) can relatively accurately conform with the statisticalaverage size. Moreover, under typical application conditions, specklesare very small, ranging generally from several hundred nanometers toseveral micrometers, therefore the integrated precision reflected by thesum (or average value) of the size of a plurality of speckles is muchhigher than the precision (approximately between 30 and 100 micrometers)required by mouse of the prior art. Hence, the sum (or average value) ofa plurality of speckle pulses may be used to determine the displacementvalue of a mouse device.

In the meantime, if two beams of laser are used to illuminate the objectat the same angle, more precise measurement results may be obtained atone dimension. As shown in FIG. 4, if the displacement in the directionof the surface of the illuminated object is d, then we have formula 3:

d=n^(λ)/2 sin^(θ), where n is the quantity of pulses of laser speckles.

If displacement within two-dimensional plane is to be measured accordingto the principle of formula 3, at least three laser beams are needed andall of the three laser beams shall not be in the same plane.

As mentioned above, various structural forms of single beam, double(multiple) beams may be used in laser speckle measurement for measuringthe displacement within a plane. These forms will be discussedrespectively hereinafter.

Embodiment 1

In FIG. 5 and FIG. 6, the device according to the present inventionincludes a mouse body, and as shown in FIG. 5 and FIG. 6, inside themouse body, an amplifying and shaping module 1, a direction identifyingand counting module 2, and a computer interface circuit 3 are disposedand connected in sequence, and the device further includes a laserdevice 4 and a photo sensor 5 for receiving laser speckle signals fromthe object surface illuminated by laser beams. Said photo sensor 5transfers the received photoelectric signals to the amplifying andshaping module 1.

Said photo sensor 5 has groups of photoelectric sensing units, whereineach group consists of two or more photoelectric sensing units alignedin a line. After laser speckle signals or laser speckle interferencesignals from the object surface illuminated by laser beams are received,relevant photoelectric signals are amplified and shaped by the group ofphotoelectric sensing units, so as to calculate the size of thecomponent of relative displacement vector between the photo sensor 5 andthe illuminated object surface in the direction of the alignment ofphotoelectric sensing units. In the meantime, the direction of saidcomponent of the relative displacement vector is determined by theskewing of the electric signals produced by these two or morephotoelectric sensing units. The photo sensor has at least two groups ofphotoelectric sensing units, wherein each group consists of two or morephotoelectric sensing units aligned in a line, and at least one grouphas an aligning direction different from the others. Two of the groupsmay intersect with each other and use common units. And the relativedisplacement vector between the photo sensor 5 and the illuminatedobject surface in the two-dimensional plane is calculated on the basisof the size and direction of the component of the relative displacementvector and the intersection angle between these vectors, which arecalculated by the group of photoelectric sensing units respectively.

As shown in FIG. 6, after laser speckle signals from the object surfaceilluminated by laser beams are received by the photo sensor 5, relevantphotoelectric signals are transferred to the amplifying and shapingmodule 1 for processing, and then they are processed by the directionidentifying and counting module 2 to determine the moving direction ofthe speckles in the entire two-dimensional plane, so as to obtain themoving direction of the mouse device. The signals processed by thedirection identifying and counting module 2 are transferred to thecomputer interface circuit 3, which may use the interface and processingcircuit module of the ordinary mouse, for sending out control signals tothe computer.

Embodiment 2

As shown in FIG. 7 and with reference to FIG. 6, the difference betweenthe present embodiment and embodiment 1 is that, in the presentembodiment, a focusing lens 6 is arranged in the light path forreceiving laser speckle signals in the photo sensor 5. As the structure,principle and operation method are the same as those of the embodiment1, unnecessary details will not be given here.

Embodiment 3

As shown in FIG. 8 and with reference to FIG. 6, the difference betweenthe present embodiment and embodiment 1 is that, in the presentembodiment, a beam splitter 8 is arranged in the light path, and thelaser beam emitted by the laser device is split into two or more beamsby the beam splitter 8 to illuminate onto one or more areas of thesurface producing laser speckle interferences, wherein each areailluminated by at least two beams.

Here, the beam splitter 8 consists of a focusing lens 6 and a pupil 7,wherein said pupil 7 has at least three light apertures 71 arranged infront of or behind the focusing lens 6. The centers of the lightapertures 71 are not in a line. Since the centers of the light apertures71 are not in a line, two-dimensional sampling of photoelectric signalsof displacement may be conducted. FIG. 8 shows only two light aperturesin one dimension, and the light aperture in the other dimension which isnot shown is similar in structure. In the present embodiment, astructural form of double (multiple) beams is used, whereas both inembodiment 1 and embodiment 2, the structural form of single beam isused. The structural form of double (multiple) beams helps to enhancethe coherence of the light source, improve the reliability and precisionof detection. As the structure of other parts and the principle andoperation method of the present embodiment are the same as those ofembodiment 1 and embodiment 2, unnecessary details will not be givenhere.

Embodiment 4

As shown in FIG. 9 and with reference to FIG. 6, in the presentembodiment, a beam splitter 8 consisting of a spectroscope 81 and aspeculum 9 is used. Laser device 4 forms two laser beams through aspectroscope 81. The split laser beams converge on the object surfaceafter being reflected by the speculum 9. FIG. 9 shows the spectroscope81 and speculum 9 in the light path in one-dimensional direction. One ortwo of the above-mentioned two laser beams may further be split by thespectroscope 81 into three or four laser beams to illuminate the objectsurface. Thus, two-dimensional sampling of photoelectric signals ofdisplacement is realized by splitting the laser beam by the spectroscope81 into multiple laser beams to illuminate the object surface. In thepresent embodiment, the structural form of double (multiple) beams isalso used. As the structure of other parts and the principle andoperation method of the present embodiment are the same as those of theabove-mentioned embodiments, unnecessary details will not be given here.

In each of the embodiments, a collimation lens 10 may also be arrangedin the emission path of the laser device 4. As shown in FIG. 9, the mainobject of arranging a collimation lens 10 is to reduce the illuminatedarea of the object surface so as to facilitate measuring. A diaphragmhaving light apertures may also be arranged in the emission path of thelaser device 4. The main function, method of usage of the diaphragm issimilar to those of the collimation lens 10, therefore unnecessarydetails will not be given here.

In embodiment 3 and embodiment 4, a beam splitter 8 is used. The laserbeam emitted by the laser device is split into two or more beams by thebeam splitter 8 to illuminate one or more areas of the surface producinglaser speckle interferences. The relative displacement vector betweenthe mouse device and the illuminated object surface producing laserspeckle interferences is reflected by means of collecting movementinformation of laser speckle interference signals.

In the present invention, as long as coherence is ensured, two or morelaser devices 4 may be used. The laser beams emitted by the two or morelaser devices 4 illuminate one or more areas of the surface producinglaser speckle interferences, wherein each area is illuminated by atleast two beams. The relative displacement vector between the mousedevice and the illuminated object surface producing laser speckleinterferences is reflected by means of collecting movement informationof laser speckle interference signals. As the principle and method ofusage are the same as the above, unnecessary details will not be givenhere.

1. A method for processing optical signals in a computer mouse,characterized in that, the relative displacement vector between themouse device and the illuminated object surface producing laser specklesis reflected by means of collecting movement information of laserspeckle signals.
 2. A method for processing optical signals in acomputer mouse, characterized in that, the relative displacement vectorbetween the mouse device and the illuminated object surface producinglaser speckle interferences is reflected by means of collecting movementinformation of laser speckle interference signals.
 3. A method forprocessing optical signals in a computer mouse as claimed in claim 1 or2, characterized in that, said laser speckle signals or laser speckleinterference signals are received by a photo sensor, and said laserspeckle signals or laser speckle interference signals are processed, soas to calculate the quantity of laser speckle pulses or laser speckleinterferences pulses received by the photo sensor, and to determine therelative displacement between the mouse device and the illuminatedobject surface producing laser speckles on the basis of the average sizeof the laser speckles or the laser speckle interferences.
 4. A methodfor processing optical signals in a computer mouse as claimed in claim3, characterized in that, said photo sensor has groups of photoelectricsensing units, wherein each group consists of two or more photoelectricsensing units aligned in a line; after laser speckle signals or laserspeckle interference signals from the object surface illuminated bylaser beams are received, relevant photoelectric signals are amplifiedand shaped by the group of photoelectric sensing units to calculate thesize of the component of relative displacement vector between the photosensor and the illuminated object surface lying in the direction of thealignment of photoelectric sensing units; in the meantime, the directionof said component of the relative displacement vector is determined bythe skewing of the electric signals produced by these two or morephotoelectric sensing units.
 5. A method for processing optical signalsin a computer mouse as claimed in claim 4, characterized in that, saidphoto sensor has at least two groups of photoelectric sensing units,wherein each group consists of two or more photoelectric sensing unitsaligned in a line, and at least one group has an aligning directiondifferent from the others, two of the groups may intersect with eachother and use common units; after laser speckle signals or laser speckleinterference signals from the object surface illuminated by laser beamsare received, relevant photoelectric signals are amplified and shaped bythese groups of photoelectric sensing units to calculate the size anddirection of the component of relative displacement vector between thephoto sensor and the illuminated object surface of the respective group,and the relative displacement vector between the photo sensor and theilluminated object surface in the two-dimensional plane is calculated onthe basis of the size and direction of the components of said relativedisplacement vector calculated by two or more groups in differentdirections and the intersection angle between the components indifferent directions.
 6. A device for processing optical signals in acomputer mouse for carrying out the method for processing opticalsignals in a computer mouse as claimed in claim 1, consisting of a mousebody; inside the mouse body, an amplifying and shaping module (1), adirection identifying and counting module (2) and a computer interfacecircuit (3) for processing photoelectric signals are disposed andconnected in sequence, characterized in that, said device furtherincludes at least one laser device (4) and a photo sensor (5) forreceiving laser speckle signals from the object surface illuminated bylaser beams; said photo sensor (5) transfers the received photoelectricsignals to the amplifying and shaping module (1).
 7. A device forprocessing optical signals in a computer mouse as claimed in claim 6,characterized in that, said device further includes at least two laserdevices (4) and a photo sensor (5) for receiving laser speckleinterference signals from the object surface illuminated by laser beams;the laser beams emitted by said two or more laser devices (4) illuminateon one or more areas of the surface producing laser speckleinterferences, wherein each area is illuminated by at least two beams.8. A device for processing optical signals in a computer mouse asclaimed in claim 6, characterized in that, said device further includesat least one laser device (4), a beam splitter (8) and a photo sensor(5) for receiving laser speckle interference signals from the objectsurface illuminated by laser beams; the laser beam emitted by said laserdevice is split into two or more beams by the beam splitter (8) toilluminate on one or more areas of the surface producing laser speckleinterferences, wherein each area is illuminated by at least two beams.